toughen

Definition

To make tough.

Etymology

From tough + -en.

Example Sentences

• "The new training program is designed to toughen the athletes."
• "A cold shower every morning will toughen your skin."
• "Although the Office of Rail and Road (ORR) had toughened its stance on new third rail electrification, gaining approval for short sections of third rail to charge the batteries could be more straightforward."